US5012409A - Operating system for a multi-tasking operating environment - Google Patents

Operating system for a multi-tasking operating environment Download PDF

Info

Publication number
US5012409A
US5012409A US07166334 US16633488A US5012409A US 5012409 A US5012409 A US 5012409A US 07166334 US07166334 US 07166334 US 16633488 A US16633488 A US 16633488A US 5012409 A US5012409 A US 5012409A
Authority
US
Grant status
Grant
Patent type
Prior art keywords
task
priority
function
system
time
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US07166334
Inventor
Mitchell S. Fletcher
Richard P. Semma
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Honeywell Inc
Original Assignee
Honeywell Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Grant date

Links

Images

Classifications

    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F9/00Arrangements for program control, e.g. control units
    • G06F9/06Arrangements for program control, e.g. control units using stored programs, i.e. using an internal store of processing equipment to receive or retain programs
    • G06F9/46Multiprogramming arrangements
    • G06F9/48Program initiating; Program switching, e.g. by interrupt
    • G06F9/4806Task transfer initiation or dispatching
    • G06F9/4843Task transfer initiation or dispatching by program, e.g. task dispatcher, supervisor, operating system
    • G06F9/4881Scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues
    • G06F9/4887Scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues involving deadlines, e.g. rate based, periodic

Abstract

A task scheduler system including an array of priority queues for use in a real time multitasking operating system including equation lists, configuration lists, a function library, input and output drivers, user-created task definition lists of major and minor tasks and interrupt handlers. The system includes task scheduling apparatus which, upon the completion of each library function, interrogates the priority queues and finds the highest priority task segment whose requested resource is available and executed, and which executes task segments in the same priority queue in round-robin fashion. The system further includes task creation apparatus and apparatus for maintaining the status of all major tasks in a system in the states of unlocked and done, unlocked and active, unlocked and waiting, locked and active, or locked and waiting. The status maintaining apparatus also includes apparatus for locking tasks into a mode of operation such that the task scheduler will only allow the locked task to execute and the normal state of priority execution is overridden, and waiting apparatus for suspending operation on a task that requires completion of a library function.

Description

BACKGROUND OF THE INVENTION

The present invention is directed to an Operating System (OS) and more particularly to a multitasking operating environment for multiplexer/ demultiplexer applications. The OS of the invention is configured using symbolic notation and user defined executable modules.

Every real time application can be defined as distinct processes, each consisting of a sequence of events as shown in FIG. 1.0. The type of event and the time at which the event is executed is unique to the application. The OS of the invention makes use of this generalization to define and coordinate processing activities within a processor. As one skilled in the art will recognize, the OS of the invention can be extended to numerous processing architectures. For ease of describing the invention, the invention will be described in terms of an OS used for a flexible multiplexer/demultiplexer system (FMDM) called an "FVOS" herein.

FMDM architecture consists of three processors: the Central Processing Unit (CPU), and Input and Output Processor (IOP), and an Arithmetic Processing Unit (APU). The IOP and APU are intended to free the CPU from time consuming inputs, outputs, and calculations. Therefore, optimal performance is achieved if all three processors are executing events at the same time commonly known as coprocessing. FVOS achieves this in the following manner.

Table 1.0 summarizes the function library which can be thought of as general purpose instructions which, when "threaded" together in a task definition list, define a task. The function library gives the user the tools to schedule his applications in symbolic notation. The function library consists of arithmetic, input/output (I/0), task creation/termination, built-in test, application module run, and reset functions. This gives the user a good mixture of functions to define his task. A conditional jump function is also included which gives the user the ability to jump over or loop within a list based on task status or timing.

The IOP executes serial input/output functions which are hardware specific For instance, an input from hardware cannot be performed while the IOP is currently performing another serial input or output. The APU calculates the results of application specific equations. The CPU performs all other functions, delegates the execution of IOP and APU functions, and initiates coprocessing. Some functions must include an address pointer in its definition. For example, the RUN function has a pointer to the location of the application module.

INPUT and OUTPUT functions have a pointer to the respective input or output buffers. A list of functions and pointers defines a task. Each task which makes up the application is defined in the same manner and then assigned a relative priority. The CPU then decodes these task lists and delegates each function to an individual processor based on priority and available resources.

The FMDM (three processor) implementation of this concept allows the capability of up to 128 task definition lists with one of eight priority levels. This is limited only by available memory and can be expanded to multiple processor systems with minimal refinement.

The word "flexible" applies to many areas of FMDM design that allow for a wide variety of payload applications. Some of these applications include use as a common/response unit for tying an experiment into a computer complex which may be resident on an aircraft, for example. The FMDM can also be used for controlling data acquisition providing autonomous control and data handling. FIG. 3 shows a generic example of an FMDM configuration including a microprocessor. FVOS was designed to free the user from the burden of interrupt handling, I/0 bus contention, system timing, etc., and at the same time, allow full access to FMDM resources. FVOS provides a multi-tasking environment with eight levels of priority, almost instant response to time critical events, and the ability to communicate with any of the IOM's via simple 1-line commands.

SUMMARY OF THE INVENTION

A task scheduler system including an array of priority queues for use in a real time multitasking operating system including equation lists, configuration lists, a function library, input and output drivers, user-created task definition lists of major and minor tasks and interrupt handlers is disclosed. The system includes means for task scheduling according to priority wherein upon the completion of each library function the priority queues are interrogated and the highest priority task segment is found whose requested resource is available and executed and wherein task segments in the same priority queue are executed in round-robin fashion. The system further includes means for task creation and therefore, means for maintaining the status of all major tasks in a system in the states of unlocked and done, unlocked and active, unlocked and waiting, locked and active, or locked and waiting. The status means also includes means for locking tasks into a mode of operation such that the task scheduler will only allow the locked task to execute and the normal state of priority execution is overridden and waiting means for suspending operation on a task that requires completion of a library function.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a symbolic diagram of real time process functional flow.

FIG. 2 shows a schematic diagram of FVOS functional structure.

FIG. 3 schematically shows a generic example of a simplex MCU FMDM configuration.

FIG. 4 illustrates the FVOS Task State diagram.

FIGS. 5(a), 5(b), and 5(c) diagrammatically illustrate the FVOS operational modes.

FIG. 6 is a functional flow chart showing the FVOS Task Scheduler Functional Flow.

FIG. 7 is a functional flow chart showing the FVOS Task Creation and Synchronization Functional Flow.

FIGS. 8A-8D illustrate FVOS Operational Mode Time Lines.

FIG. 9 shows a schematic diagram of a possible control system configuration utilizing the operating system of the invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The instant invention comprises a Operating System (OS) comprising three levels of software which create a multi-tasking environment for user applications. FIG. 2 is a schematic diagram of one embodiment of the invention which is an OS used in an FMDM processing system or "FVOS". As shown in FIG. 2, the first level comprises input/output (I/0) drivers 12 and interrupt handlers 14. The task creation and synchronization is implemented as one of the interrupt handlers. The next level comprises a task scheduler 20 and the last level comprises a function library 30. FVOS provides a multi-tasking operating environment for flexible multiplexer/ demultiplexer (FMDM) applications and can control execution of multiple tasks and respond quickly to high priority tasks at time critical events. In one embodiment of the invention FVOS is capable of controlling execution of up to 128 tasks.

Referring again to FIG. 2, the user must supply the equation lists 3, configuration lists 4, and the application modules. These lists and modules are created using a Z80 macro assembler and the FVOS macro function library. Although it will be evident to those skilled in the art that the instant invention may be used with many types of real time control applications, such as industrial controllers, the description of the preferred embodiment as follows refers to the use of the operating system in connection with an FMDM processing system which is used in connection with monitoring and controlling multiple scientific experiments being carried out in real time and contemporaneously with each other.

The task scheduler 20 coordinates the central processing unit (CPU), arithmetic processing unit (APU), and I/0 resources. On the basis of priority, the task scheduler 20 chooses the priority of execution of functions. Following the execution of each function, control returns to the task scheduler 20. Task scheduler 20 is described in further detail below.

The function library 30 consists of various elementary operations which, when organized in a sequence, form a task. Some functions use the I/0 drivers, and others the APU. The only way that a function is executed is by initiation from the task scheduler 20. The equation lists, task definition lists, and application modules are not part of FVOS but are an important part of FVOS operation with regard to satisfying a particular application. Equation lists define application-specific numerical equations which shall be interpreted by the calculate function and executed by the APU. The task definition lists are application-specific lists which define the fundamental sequential operations that make up the tasks, the relative priority among neighboring tasks, and the execution frequency of each task. The task definition lists shall be interpreted by the task scheduler 20 to orchestrate the execution of functions. The application modules are linkable object code modules required for the application.

FVOS Functional Description

FVOS is based on a top-down structured definition of all tasks to be executed. Applications are defined in a structured manner and each application can be represented as one task or multiple tasks. Each task is assigned a relative priority and consists of functions from the function library, which are task segments. Execution of these task segments shall be started in series by the CPU, but will be executed in parallel by the IOP and APU.

The major functional portions of FVOS are the initialization module (not shown), the task scheduler 20, and the function library 30. A detailed break down of FVOS software modules along with their respective functions is shown at Table 2. The initialization module prepares FVOS for operation. The task scheduler 20 delegates execution of all tasks. The function library 30 contains the commands which are available to the user for defining an application and symbolic notation.

At OS Initialization

In one embodiment of the OS, called the FVOS as used with the FMDM system, the following initialization procedures are followed. Upon entry, FVOS is initialized, task zero (the first user defined task) is placed in the highest priority queue, and the task scheduler is entered. FVOS initialization consists of: (1) zero out RAM, (2) initialize all pointers, (3) set up interrupt vectors and priority memory, (4) move three pages of EEPROM into RAM, (5) set up minor and major frame timing, and (6) enable interrupt.

Task zero is initiated by placing its first function in the highest priority queue. Control is then given to the task scheduler 20 which executes task segments currently in the queues based on priority and resource availability. Other tasks are executed by their first element being added to the queue by task zero, the task creation and synchronization routine, or by special interrupt. Each task is executed as a series of task segments, one segment at a time. The task segments ready to be executed are maintained in a series of queues which are ordered with the highest priority first. When a task segment is completed, the next task segment within that major task is added to the queue and priority is reevaluated by the task scheduler to determine which task segment to execute next. Tasks of the same priority are executed in a round-robin fashion with no task suspension.

Task Scheduler

The task scheduler 20 controls execution of all tasks based on priority and resource availability, by maintaining a series of pointers, status registers, counters, and a plurality of priority queues. In the FVOS version of the instant invention, the number of levels of priority queues is 8. Following power up of the system in normal operation, the first major task is executed and is typically reserved by the user for initialization functions. The task scheduler is reentered following the execution of each task segment. The task creation and synchronization portion of the task scheduler is entered at each tick of the system clock (each 10 msec).

The task scheduler allows the CPU to execute the first task (highest priority) in the queue. If the function which a minor task segment calls is busy (e.g., waiting for data, such as completing a calculation or still in the process of serially transferring an input from or an output to an IOM), the task scheduler will proceed to the next element in the queue. This approach maximizes effective processing performance because processing resources such as scientific arithmetic computation and input/output will be executed in parallel with the CPU functions.

The task scheduler also includes means for maintaining the status of every major task. Major task statuses defined as follows (all other states are illegal in the system):

__________________________________________________________________________00 H = UNLOCKED and DONE              81 H = LOCKED and ACTIVE01 H = UNLOCKED and ACTIVE              83 H = LOCKED and WAITING03 H = UNLOCKED and WAITING__________________________________________________________________________

A locked task is defined as one which is in the "locked" operating mode. A done task is defined as one that is waiting to be created. A task is "created" when it is put into the priority queue for execution. An active task is defined as a task that is currently experiencing execution (i.e., has an element in the queue). A task is defined as waiting if it has initiated execution of an APU or I/0 function but the function is not 100% completed. As shown in FIG. 4, all tasks are done immediately after initialization. Once a task is active locked, it is returned to the active unlocked state by executing an unlock or done function. In the locked mode 304, a task can go from active to waiting 306 and back again to active. In the unlocked mode, a task can go from active to done or waiting but cannot go from done to waiting or from waiting to done.

The task creation and synchronization portion of the task scheduler is the interrupt service routine for the programmable timer. At each tick of the system clock (every 10 msec), the FMDM Mission Elapsed Time (MET) is incremented, along with the minor and major frame timing. This time can be synchronized with Greenwich Mean Time if necessary. Tasks are created based on major or minor frame timing, a specified delay, or MET. The task scheduler maintains a list of tasks to be created at a specific minor frame, major frame, MET, or delay time. At the correct time, each element of the list is evaluated and if the element has matured, it is put in the priority queue for execution.

Function Library

The function library gives the user the tools to create his applications in symbolic notation. The function library consists of arithmetic, I/0, task creation/termination, BITE, application module RUN, memory manipulation, and RESET functions. A conditional jump function is also included which offers the ability to jump over or loop, based on task status, timing, or a user-defined flag. A task segment shall be a function with specific inputs and outputs defined in the task configuration list. A list of task segments form a task. Application modules can be written in a high-level language or assembly language and then be executed by the RUN function.

The function library can be thought of as a collection of general-purpose instructions which, when "threaded" together by the task configuration list, form a task. Each user function will be written in symbolic notation which, when expanded by a set of FVOS macros, will form the configuration list. The macro definitions shall be made to operate with a Tektronix Z80 assembler.

FVOS Functional Flow

FVOS has three primary operational modes, as shown in FIG. 5. These tasks shall be the normal (task-to-task) operational mode, the locked operational mode, and the reserved-resources operational mode. Task-to-task operation is shown in FIG. 5(a) as the normal operational mode. The highest priority task is executed and the other tasks T1-T4, generally designated 7, remain in a queue waiting for their turn. FIG. 5(a) shows an array of priority queues 5. In the FVOS embodiment of the present invention, 8 queues contain the address pointers and priority status for 8 subtasks, also called elements. Tasks of the same priority are executed in a round-robin fashion with no task suspension. After the current task has been executed, priority is reevaluated and the highest priority task is executed.

Still referring to FIG. 5(a), for example, the current task being executed is represented by the box labelled Tex, once that task is executed, the task scheduler again reviews the priority queues searching for the next task of the highest priority. Assuming that the task of the highest priority is task T1, this would be the next task executed. If tasks T1, T2, T3, and T4 are all the same priority, task T1 would be executed first, T2 second et. seq., since the task would then be taken in a round-robin fashion.

Locked Operational Mode

Referring now to FIG. 5(b), a symbolic diagram of the locked operational mode is shown. Locked operation mode is scheduled when a sequence of events within a major task is time critical. As noted above, a major task is a series of subtasks which is to be completed within a major time frame. As shown in FIG. 5(b) by the box labelled Tx, a locked task overrides normal priority and has all resources available to it. The locked task is executed function after function without evaluating the queue until a "done" or "unlock" function is encountered. The done or unlock functions would be executed as subtasks within the major task. A task is "done" when all subtasks have been executed. The "done" function tells the task scheduler to stop working on that task. FVOS then returns to normal task to task operational mode as shown in FIG. 5(a).

Reserved-Resources Operational Mode

The reserved-resources operational mode as shown in FIG. 5(c) is provided when quick response to an expected event is required. FVOS waits for an event to occur; when the event occurs, the reserved task is executed until a "done" or "unlock" function is encountered, which returns FVOS to normal operational mode. If the event does not occur within the specified time out period (supplied by the user), then an error is flagged by the task scheduler. In on embodiment of the invention, 8 separate interrupts can signal the occurrence of the event. These can be either timed interrupts, or interrupts based upon stimulus (such as pushing a button) from outside of the FVOS system. FVOS determines whether or not to go into the reserved-resources operational mode, or any of its operational modes, bY searching through the array of priority queues and checking if a task or subtask requires resources to be reserved.

Time Lines

The operation of FVOS is divided into two groups: the task scheduler, which executes between execution of each task segment, and the task creation and synchronization module, which is driven by the programmable timer interrupt and executed every 10 msecs. The functional flow of the task scheduler is shown in FIG. 6.

Referring now to FIG. 6, note that FVOS has two entry points: a warm start location 50 and a cold start location 55. The primary difference between the two functions is that a warm start does not reset the MET but the cold start does. Also, a cold start evaluates its source of entry (i.e., go to 0000H or power up) and sets the power up status flag accordingly.

The task scheduler decides which task is to be executed next, based on the current FVOS operating mode. The frequency of execution for the task scheduler is once for every function that is executed.

Still referring to FIG. 6, after initialization 52, the task scheduler operates in loop 60 beginning at activity 65 which is means for obtaining the next task from the priority queues. Next, the task scheduler goes through decision means 70 to determine whether the next task is a lock function. If the task is a lock function, the task is executed element-by-element without evaluating the queue by execution means 72 until an unlock or done element is encountered. Following that same functional line, when the unlock or done is encountered at execution means 72, the task scheduler executes the next function or subtask or, if done, goes to the box 65 to obtain the next task from the queues. If at decision means 70 the next task is not a lock function, the task scheduler functionally proceeds to decision means 75 to determine whether or not the task is a reserved function. If the task is a reserved function, the task scheduler goes into decision means 80 to determine whether or not a time critical event has occurred at which time the function will be executed in box 72.

If the next task is not a reserved function, decision means 82 is entered wherein the task scheduler determines whether or not the next task is a task creation function. If it is, the new task is put into the proper list or queue pursuant to functional box 85 which then enters execute next function means 90. If the next task is not a task creation function, the task scheduler checks for a done subtask and puts the next function in the proper list or queue.

Now referring to FIG. 7, the task creation and synchronization module 300 is shown in the form of a functional flow diagram. The task creation and synchronization foreground functional flow keeps track of time, adds tasks to the priority queue based on MET, and performs various housekeeping functions. This module is entered once for every programmable timer interrupt, which FVOS initializes to a 10-msec rate. Task creation functions within this module are conditional based on MET, minor-frame timing, and major-frame timing. Each user application has minor and major time frames associated with it. Minor frames refer to minor time frames as used herein and are the number of 10-msec system ticks from 1 to 256. A major frame refers to a major time frame as used herein and is comprised of a number of minor frames from 1 to 256. Major frames and minor frames can be thought of as fast inner loops and slower outer loops in terms of program functional flow, respectively. The user can define the number of major and minor frames to suit the users application needs.

Referring again to FIG. 7, the task creation and synchronization module enters the functional flow at functional clock 100 where the MET is incremented by 10 milliseconds. Decision means 105 queries the MET list and if the list contains mature tasks, the first element of these tasks are added to the priority queues at functional block 110. In the nomenclature of FVOS "create all mature elements" means to add those subtasks to the priority queues which have "matured" (i.e., those elements which are ready for execution). If the MET list is empty or if all mature elements have been created, the module then enters the decision means 115 and checks the delay list for elements. The delay for each item in the delay list is decremented by 10 msec. When delay is equal to zero, elements in the delay list are "mature" and are added to the list in functional block 120. If the delay list is empty or if all mature elements have been created, the module functionally executes the next decision means 120 to query whether or not the next minor frame is beginning. If the next minor frame is beginning, then all elements in the minor frame list are created in functional block 125. If a next minor frame is not beginning or if all elements have been created, the module proceeds to decision means 130 to check if the next major frame is beginning and, if so, it creates all elements in the major frame list at functional block 135. Finally, the module checks to see if a reserved time out has occurred at decision means 140. The decision time out is a safety feature wherein if resources have been reserved, a time limit is set by the user for reservation of those resources while awaiting a time critical event. If the reserve time out occurs before the time critical event occurs, a reserve time out error is sent at point 145. If no reserve time out has occurred, the FVOS returns from the interrupt back into the task scheduler module.

FIG. 8 illustrates calculated time lines for FVOS initialization and each of the three operational modes. Following FVOS initialization, one of the three operational modes is entered. Required context switching times for each operational mode is also shown in FIG. 8.

Note that the times in FIG. 8 are calculated based on only one element in the highest-priority queue, which is an almost ideal situation. Numerous situations can exist depending on the current status of each major task and the arrangement of elements in the priority queue. For purposes of estimating context-switching times, the following variations are applied to the time lines of FIG. 8 to satisfy each special situation. In the following variations, the task segment which the task scheduler chooses to execute is referred to as the task segment of interest.

1. If the previous task segment is the last

segment of that task, add 43.5 microseconds to the task scheduler execution time.

2. If the task segment of interest is an I/0 or APU function, add 10 percent to the task scheduler execution time.

3. If the task segment of interest is not the highest priority level, add 16.5 microseconds for each priority level below the highest priority level.

4. If an I/0 or APU function is currently coprocessing and is of a higher priority than the task segment of interest, add 61.25 microseconds for each of the I/0 or APU functions.

Interrupts

In one embodiment of the invention as used with an FMDM, the FMDM interrupt structure is Z80 interrupt mode 2. There are 9 FMDM interrupts organized in a priority fashion. The APU interrupt, IOM disable interrupt, programmable timer interrupt, and IOM transfer completed ("done") interrupt are transparent to the user, while IOM number zero interrupt, flexible interrupt, external interrupt, error interrupt, and non-maskable interrupt are user defined. The non-maskable interrupt (NMI) occurs upon the loss of power to the FMDM. The NMI service routine prepares for and executes a graceful power down sequence.

The IOM transfer complete (done) interrupt occurs following every input/output transfer and signals that the I/0 transfer has completed and data is available at the I/0 controller (another I/0 transfer can now occur). This interrupt is transparent to the user and is completely serviced by FVOS.

As one skilled in the art will readily recognize, there are many potential uses for the operating system of the invention. One possible use would be to control a materials processing experiment wherein sensors would provide inputs to the operating system related to certain tasks, those tasks would be prioritized and executed by the operating system and the operating system would output signals to control means for operating specified functions. For example, a user of the system could operate an experiment to grow crystals. The user would start with an appropriate liquid solution which would grow crystals under the right environmental conditions. The operating system would wait for the user to initiate the process, as by pushing a button. The operating system would then receive inputs from a number of sensors in parallel and perhaps operate multiple crystal growing experiments in parallel, while using one controller.

One possible scenario would be where the operating system would command a vacuum chamber to evacuate after the liquid solution had been input into the vacuum chamber. The operating system would then monitor the pressure within the vacuum chamber by receiving inputs from pressure sensors inside the vacuum chamber. When the vacuum chamber reached a certain pressure, for example, 10-8 TOR, it would then start a heater which would ramp up at a controlled rate of ascent. The operating system, through inputs from the outside sensors, would continuously monitor the temperature inside of the vacuum chamber. At the same time, it would provide for adjusting the temperature via a control means responding to the temperature measurements. A third sensor could measure the weight of the crystal and when it arrived at a predetermined weight, the above process would be reversed, returning the chamber to normal atmospheric and room temperatures.

Another possible application for this operating system would be to attach it to sensors within a building The sensors could operate the environmental controls within the building including heating and air-conditioning. It would be possible, using this operating system, to perform many other tasks at the same time, such as using the MET function to turn lights on and off. A function such as turning the lights in a building on and off would be more of a "major frame" task, or an outer loop task since it can be done over long periods of time and does not require split second timing.

FIG. 9 shows a control system using the operating system of the invention including sensing means SM, the operating system OS, and control means CM. The sensing means SM comprises a plurality of sensors having a plurality of outputs 200 and a plurality of inputs 202. The operating system has inputs and outputs corresponding to the stimulus received from the sensing means which would result in tasks being performed and sending signals in the form of electronic voltages via the outputs of the operating system 210 to the inputs of the control means. Control means CM has outputs 215 which carry a control signal to an external device. Of course, it is not necessary to have a plurality of inputs and outputs, but it makes the most efficient use of the operating system. The operating system could work with a single sensor and a single controller in a given circumstance.

While there has been shown and described a preferred embodiment of the invention, those skilled in the art will appreciate that various changes and modifications may be made to the illustrated embodiment without departing form the true spirit and scope of the invention which is to be determined from the appended claims.

                                  TABLE 1.0__________________________________________________________________________FVOS FUNCTION SUMMARY      EXECUTED BYFUNCTION NAME      CPU         IOP            APU               DESCRIPTION__________________________________________________________________________RUN        X        RUN APPLICATION MODULECALCULATE        X  PERFORM CALCULATION EQUATIONINPUT         X     INPUT DATA FROM AN I/O MODULEOUTPUT        X     OUTPUT DATA TO AN I/O MODULEECHO          X     ECHO DATA FROM AN I/O MODULE TO AN I/O MODULECT-DELAY   X        CREATE A TASK AFTER A DELAY TIMEOUTCT-MAJOR   X        CREATE A TASK AT NEXT MAJOR TIMING FRAMECT-MET     X        CREATE A TASK AT NEXT MINOR TIMING FRAMEINQUIRE    X        CREATE A TASK AT MISSION ELAPSED TIMEBITE       X  X     PERFORM BUILT-IN TESTSJUMP       X        CONDITIONAL JUMPLOCK       X        OVERRIDE PRIORITY-EXECUTE ONE TASKUNLOCK     X        INVERSE OF LOCKLOAD                LOAD DATA FROM RAM TO EEPROMRESERVE    X        RESERVE I/O RESOURCE FOR TIME CRITICAL EVENTPUTC       X        PUT CHARACTER TO RS-232CGETC                GET CHARACTER FROM RS-232CIOC        X        CONTROL HEARTBEAT CONTROLLERMASK          X     CHANGE INTERRUPT STRUCTUREMRESET        X     RESET ALL FMDM HARDWAREPROG       X        PROGRAM EEPROMSSETIME     X        SET THE FMDM MISSION ELAPSED TIME REFERENCE__________________________________________________________________________

                                  TABLE 2__________________________________________________________________________FVOS SOFTWARE MODULE FUNCTIONAL SUMMARYSOFTWARE                            FUNCTIONMODULE TYPE      MNEMONIC              NAME             (SEE NOTE)__________________________________________________________________________Interrupt Handler      TSK.sub.-- CS              Programmable Timer Interrupt                               T      NMI.sub.-- SR              Non-Maskable Interrupt                               U      ONE.sub.-- 6              IOM Disable Interrupt                               D      FLEXI   Flexible Interrupt                               U      DONEI   DONE Interrupt   IO      APUI    APU Interrupt    A      IOMI    IOM #0 Interrupt IOU      EXTI    External Interrupt                               U      ERRORI  Error Interrupt  UD      MASK    Modify Interrupt Mask                               UTask Scheduler      TS      Task Scheduler   TTask Creation      CT.sub.-- DLY              Create task after a delay                               TFunctions  CT.sub.-- MET              Create task at Mission                               T              Elapsed Time      CT.sub.-- MAJ              Create task at major frame                               T      CT.sub.-- MIN              Create task at minor frame                               TArithmetic CALC    "Calculate" function                               AFunctionsInput/Output      INPUT   Input function   IFunctions  OUTPUT  Output function  O      ECHO    Echo input to output                               IO      PUTC    Put character to RS-232 port                               O      GETC    Get character from RS-232 port                               I      MRESET  Master reset individual IOMs                               IOPriority   LOCK    "Lock"  function TOverride Functions      UNLOCK  "Unlock" function                               T      RESERV  Reserve processing resources                               TEEPROM Functions      LOAD    Load program from EEPROM to                               U              RAM      PROG    Program EEPROM   UConditional      JMP.sub.-- Z              Jump on zero     T      JMP.sub.-- NZ              Jump on not zero T      JMP.sub.-- P              Jump on positive T      JMP.sub.-- N              Jump on negative T      JUMP    Jump always      TBuilt-In Test      BITEPS  Power Supply BITE                               DFunctions  BITEMM  Memory Module BITE                               D      BITECPU CPU Module BITE  D      BITEAPU APU Module BITE  D      BITEIO  I/O Module BITE  DMiscellaneous      RUN     Run an application module                               UFunctions  SETIME  Set FMDM elapsed time                               T      INQUIRE Status inquiry function                               D      INIT    Initialize FVOS  T      PWRUP   Put power-up status to                               D              pointer      BSR     Put BITE status register to                               D              pointer      LOAD.sub.-- B              Load memory byte with value                               U      LOAD.sub.-- W              Load memory word with value                               U      RDERR   Read error register and put                               D              to pointer      IOC     Turn the IO Controller on,                               IO              off, or to obtain status__________________________________________________________________________ NOTES: I = INPUT, O = OUTPUT, T = TASK COORDINATION, D = DIAGNOSTICS, U = USERDEFINED, A = ARITHMETIC

                                  TABLE 10__________________________________________________________________________FVOS INTERRUPT SUMMARYINTERRUPT   PRIORITY          SOURCE    OCCURRANCE                             RESPONSE__________________________________________________________________________APU     Lowest Arithimetic                    Once for every                             Continue calculations          Processing Unit                    APU command                             or get resultIOM #0         IOM #0    User-defined                             User-definedIOM            1.6-second BITE                    Every 1.6                             Create a task thatDISABLE        timer     seconds  resets IOM Disable                    timerEXTERNAL       User experiment                    User-defined                             User-defined          external to FMDMFI             User-defined                    User-defined                             User-defined          (FMDM slot #11)ERROR          Error register                    Upon error                             User-defined                    conditionsPROG.          Programmable                    Every 10 msec                             Task creation andTIMER          Timer              synchronization                             moduleDONE           IOM transfer                    Once for every                             Get input and/or set          completed input/output                             IOM status to not                             busyNMI     Highest          Power Supply                    Upon loss of                             User-defined          hardware  power    (preparation for                             power loss)__________________________________________________________________________

Claims (5)

The embodiments of the invention in which an exclusive property or right is claimed are defined as follows:
1. A task scheduler system, including an array of priority queues for use in a real time multitasking operating system including equation lists, configuration lists, a function library, input and output drivers, user-created task definition lists of major and minor tasks, including major and minor task elements, and interrupt handlers, initialized to have programmable timer interrupts, comprising:
(a) means for task scheduling according to priority wherein upon the completion of each library function the priority queues are interrogated and the highest priority task segment is found whose requested resource is available and executed and wherein task segments in the same priority queue are executed in round-robin fashion,
and wherein the task scheduling means further includes means for maintaining the status of all major tasks in the system in the states of unlocked and done, unlocked and active, unlocked and waiting, locked and active, or locked and waiting including means for locking tasks into a mode of operation so as to only allow the locked task to execute overriding the normal state of priority execution, and wherein the task scheduling means still further includes waiting means for suspending operation on a task that requires completion of a library function; and
(b) means for task creation responsive to programmable timer interrupts including means for interrogating the task definition lists and means for creating all major and minor task elements from the task definition lists so as to create major and minor tasks which are added to the priority queues.
2. The system of claim 1 wherein the array of priority queues comprise eight queues.
3. The system of claim 1 wherein the number of task definition lists is a maximum of 128.
4. A method of scheduling tasks included in an array of priority queues for use in a real time multitasking operating system, including equation lists, configuration lists, a function library, input and output drivers, user-created task definition lists of major and minor tasks, including major and minor task elements, and interrupt handlers, initialized to have programmable timer interrupts comprising the steps of:
(a) task scheduling according to priority wherein upon the completion of each library function the priority queues are interrogated and the highest priority task segment is found whose requested resource is available and executed and wherein task segments in the same priority queue are executed in round-robin fashion and where the task scheduling further includes the steps of
maintaining the status of all major task in a system of the states of unlocked and done, unlocked and active, unlocked and waiting, locked and active, or locked and waiting including locking tasks into a mode of operation so as to only execute the locked task and override the normal state of priority execution, and waiting for suspending operation on a task that requires completion of a library function; and
(b) creating tasks in response to the programmable timer interrupts including the steps of interrogating the task definition lists and creating all major and minor task elements form the task definition lists so as to create major and minor tasks.
5. The method of claim 4 further including the step of reserving resources for response to the occurrence of a time critical event.
US07166334 1988-03-10 1988-03-10 Operating system for a multi-tasking operating environment Expired - Fee Related US5012409A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US07166334 US5012409A (en) 1988-03-10 1988-03-10 Operating system for a multi-tasking operating environment

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US07166334 US5012409A (en) 1988-03-10 1988-03-10 Operating system for a multi-tasking operating environment
EP19890104020 EP0332148A3 (en) 1988-03-10 1989-03-07 Multi-tasking operating system
CN 89101252 CN1038712A (en) 1988-03-10 1989-03-09 Operating system for a multi-tashking operating environment
JP5948989A JPH01316831A (en) 1988-03-10 1989-03-10 Task scheduling device and method

Publications (1)

Publication Number Publication Date
US5012409A true US5012409A (en) 1991-04-30

Family

ID=22602827

Family Applications (1)

Application Number Title Priority Date Filing Date
US07166334 Expired - Fee Related US5012409A (en) 1988-03-10 1988-03-10 Operating system for a multi-tasking operating environment

Country Status (4)

Country Link
US (1) US5012409A (en)
EP (1) EP0332148A3 (en)
JP (1) JPH01316831A (en)
CN (1) CN1038712A (en)

Cited By (109)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991020041A1 (en) * 1990-06-11 1991-12-26 Supercomputer Systems Limited Partnership Multiple request toggling priority arbitration system
US5208914A (en) * 1989-12-29 1993-05-04 Superconductor Systems Limited Partnership Method and apparatus for non-sequential resource access
US5249297A (en) * 1991-04-29 1993-09-28 Hewlett-Packard Company Methods and apparatus for carrying out transactions in a computer system
US5307482A (en) * 1992-01-28 1994-04-26 International Business Machines Corp. Computer, non-maskable interrupt trace routine override
US5361365A (en) * 1989-11-06 1994-11-01 Sharp Kabushiki Kaisha Microprocessor for selectively performing cold and warm starts
US5377352A (en) * 1988-05-27 1994-12-27 Hitachi, Ltd. Method of scheduling tasks with priority to interrupted task locking shared resource
US5392433A (en) * 1992-09-25 1995-02-21 International Business Machines Corporation Method and apparatus for intraprocess locking of a shared resource in a computer system
US5392429A (en) * 1991-10-11 1995-02-21 At&T Corp. Method of operating a multiprocessor computer to solve a set of simultaneous equations
US5428789A (en) * 1993-08-27 1995-06-27 Waldron, Iii; Theodore C. Method and apparatus for optimizing user response time in a priority preemptive operating system
US5430874A (en) * 1992-03-06 1995-07-04 Hitachi, Limited Control method and system for managing memory control blocks of programmed tasks in a multi-processing system
US5452452A (en) * 1990-06-11 1995-09-19 Cray Research, Inc. System having integrated dispatcher for self scheduling processors to execute multiple types of processes
US5465335A (en) * 1991-10-15 1995-11-07 Hewlett-Packard Company Hardware-configured operating system kernel having a parallel-searchable event queue for a multitasking processor
US5471618A (en) * 1992-11-30 1995-11-28 3Com Corporation System for classifying input/output events for processes servicing the events
US5504904A (en) * 1994-02-23 1996-04-02 International Business Machines Corporation Personal computer having operating system definition file for configuring computer system
US5506988A (en) * 1990-06-26 1996-04-09 Siemens Aktiengesellschaft Program-controlled communication installation
US5511220A (en) * 1994-09-01 1996-04-23 Perlman; Noah Multi-user computer system with a clock driven batch dispatching mechanism
US5513351A (en) * 1994-07-28 1996-04-30 International Business Machines Corporation Protecting a system during system maintenance by usage of temporary filenames in an alias table
US5513354A (en) * 1992-12-18 1996-04-30 International Business Machines Corporation Fault tolerant load management system and method
US5553287A (en) * 1989-11-28 1996-09-03 International Business Machines Corporation Methods and apparatus for dynamically using floating master interlock
US5640563A (en) * 1992-01-31 1997-06-17 International Business Machines Corporation Multi-media computer operating system and method
US5715474A (en) * 1992-04-30 1998-02-03 Motorola, Inc. Simultaneous control of radio frequency modem in a multi-tasking system using a single session manager program with separate command queue for each application program
US5742825A (en) * 1994-09-30 1998-04-21 Microsoft Corporation Operating system for office machines
US5940612A (en) * 1995-09-27 1999-08-17 International Business Machines Corporation System and method for queuing of tasks in a multiprocessing system
US5954792A (en) * 1996-12-30 1999-09-21 Cadence Design Systems, Inc. Method for schedule validation of embedded systems
US5999963A (en) * 1997-11-07 1999-12-07 Lucent Technologies, Inc. Move-to-rear list scheduling
WO2000006084A2 (en) * 1998-07-31 2000-02-10 Integrated Systems Design Center, Inc. Integrated hardware and software task control executive
US6049867A (en) * 1995-06-07 2000-04-11 International Business Machines Corporation Method and system for multi-thread switching only when a cache miss occurs at a second or higher level
US6078942A (en) * 1996-04-25 2000-06-20 Microsoft Corporation Resource management for multimedia devices in a computer
US6105050A (en) * 1998-08-25 2000-08-15 International Business Machines Corporation System for resource lock/unlock capability in multithreaded computer environment
US6105049A (en) * 1998-08-25 2000-08-15 International Business Machines Corporation Resource lock/unlock capability in multithreaded computer environment
US6112222A (en) * 1998-08-25 2000-08-29 International Business Machines Corporation Method for resource lock/unlock capability in multithreaded computer environment
US6182120B1 (en) * 1997-09-30 2001-01-30 International Business Machines Corporation Method and system for scheduling queued messages based on queue delay and queue priority
US6215559B1 (en) * 1998-07-31 2001-04-10 Eastman Kodak Company Image queing in photofinishing
US6260058B1 (en) * 1994-07-19 2001-07-10 Robert Bosch Gmbh Process for controlling technological operations or processes
US6334159B1 (en) * 1998-12-22 2001-12-25 Unisys Corporation Method and apparatus for scheduling requests within a data processing system
US6408324B1 (en) * 1997-07-03 2002-06-18 Trw Inc. Operating system having a non-interrupt cooperative multi-tasking kernel and a method of controlling a plurality of processes with the system
US20020082721A1 (en) * 2000-12-27 2002-06-27 Armin Amrhein Programming of cyclical machines
US20020082718A1 (en) * 2000-12-27 2002-06-27 Armin Amrhein Method of operating an industrial controller
WO2002052370A2 (en) * 2000-12-26 2002-07-04 Bull Hn Information Systems Inc. Software and data processing system with priority queue dispatching
US20030009508A1 (en) * 2001-06-26 2003-01-09 Troia Terry A. Method and system for providing processor task scheduling
US6510460B1 (en) * 1997-12-18 2003-01-21 Sun Microsystems, Inc. Method and apparatus for enforcing locking invariants in multi-threaded systems
US20030037091A1 (en) * 2001-08-09 2003-02-20 Kozo Nishimura Task scheduling device
US6549928B1 (en) * 1998-04-29 2003-04-15 Xerox Corporation Machine control integrating event based model with task based model
US6633942B1 (en) * 1999-08-12 2003-10-14 Rockwell Automation Technologies, Inc. Distributed real-time operating system providing integrated interrupt management
US20030198462A1 (en) * 2002-04-23 2003-10-23 Jim Bumgardner Conflict Manager for a Video Recorder
US20030206719A1 (en) * 2002-04-23 2003-11-06 Jim Bumgardner Storage Management for a Video Recorder
US20030225817A1 (en) * 2002-06-04 2003-12-04 Prashanth Ishwar Concurrent execution of kernel work and non-kernel work in operating systems with single-threaded kernel
US6678713B1 (en) * 1998-04-29 2004-01-13 Xerox Corporation Machine control using a schedulerlock construct
US20040139442A1 (en) * 2001-09-20 2004-07-15 Keiichi Miyamoto Task switching system, task switching method and dsp modem
US20040156614A1 (en) * 2003-02-10 2004-08-12 Pioneer Digital Technologies, Inc. Tuner sharing video recorder system architecture
US20040213557A1 (en) * 2003-04-23 2004-10-28 Pioneer Digital Technologies, Inc. Non-hierarchical interface screens for use in a video recorder
US6829764B1 (en) * 1997-06-23 2004-12-07 International Business Machines Corporation System and method for maximizing usage of computer resources in scheduling of application tasks
US20050044340A1 (en) * 2003-08-18 2005-02-24 Kitrick Sheets Remote translation mechanism for a multinode system
US20050044128A1 (en) * 2003-08-18 2005-02-24 Scott Steven L. Decoupled store address and data in a multiprocessor system
US20050086665A1 (en) * 2003-10-16 2005-04-21 Matsushita Electric Industrial Co., Ltd. Autonomous device driver
US20050262255A1 (en) * 2004-04-30 2005-11-24 Microsoft Corporation System applications in a multimedia console
US20050267792A1 (en) * 2004-05-28 2005-12-01 Sumit Mehrotra Method and system for laboratory management
US20060085368A1 (en) * 2004-10-14 2006-04-20 International Business Machines Corporation Autonomic SMT System tuning
US7036002B1 (en) * 1997-06-26 2006-04-25 Cp8 Technologies System and method for using multiple working memories to improve microprocessor security
US20060095914A1 (en) * 2004-10-01 2006-05-04 Serguei Mankovski System and method for job scheduling
US20070168539A1 (en) * 2005-12-29 2007-07-19 Guideworks, Llc Systems and methods for managing a status change of a multimedia asset in multimedia delivery systems
US20070174336A1 (en) * 2005-12-29 2007-07-26 Guideworks, Llc Systems and methods for resolving conflicts and managing system resources in multimedia delivery systems
US20070250834A1 (en) * 2006-04-19 2007-10-25 Orion Electric Co., Ltd. Information processing device including manipulation task reservation function, manipulation task reservation processing program and manipulation task reservation processing method
US7305675B1 (en) * 2002-01-11 2007-12-04 Advanced Micro Devices, Inc. Processing tasks with failure recovery
US20070283127A1 (en) * 2003-08-18 2007-12-06 Cray Inc. Method and apparatus for indirectly addressed vector load-add-store across multi-processors
US20080046935A1 (en) * 2006-08-18 2008-02-21 Krakirian Haig H System and method for displaying program guide information
US20080077957A1 (en) * 1996-06-14 2008-03-27 Starsight Telecast, Inc. Television schedule system and method of operation for multiple program occurrences
US20080140896A1 (en) * 2006-11-10 2008-06-12 Seiko Epson Corporation Processor and interrupt controlling method
US20080178186A1 (en) * 2004-10-14 2008-07-24 International Business Machines Corporation Apparatus and Methods for Performing Computer System Maintenance and Notification Activities in an Opportunistic Manner
US20080184297A1 (en) * 2001-02-21 2008-07-31 Ellis Michael D Systems and methods for interactive program guides with personal video recording features
US20080250433A1 (en) * 1993-07-19 2008-10-09 Apple Inc. Object-oriented operating system
US20090007123A1 (en) * 2007-06-28 2009-01-01 Samsung Electronics Co., Ltd. Dynamic Application Scheduler in a Polling System
US20090024665A1 (en) * 2007-07-17 2009-01-22 Ricoh Company, Limited Method and apparatus for processing data
US20090063242A1 (en) * 2007-09-04 2009-03-05 International Business Machines Corporation System and method for providing automatic task assignment and notification
US7503048B1 (en) 2003-08-18 2009-03-10 Cray Incorporated Scheduling synchronization of programs running as streams on multiple processors
US7519771B1 (en) 2003-08-18 2009-04-14 Cray Inc. System and method for processing memory instructions using a forced order queue
US7543133B1 (en) 2003-08-18 2009-06-02 Cray Inc. Latency tolerant distributed shared memory multiprocessor computer
US20090150888A1 (en) * 2006-04-03 2009-06-11 Beijing Watch Data System Co., Ltd. Embedded operating system of smart card and the method for processing the task
US20090208961A1 (en) * 2008-02-12 2009-08-20 Pacific Biosciences Of California, Inc. Compositions and methods for use in analytical reactions
US7647591B1 (en) * 2001-09-26 2010-01-12 Palmsource Inc. Method for dynamically enabling the expansion of a computer operating system
US20100135639A1 (en) * 2005-09-30 2010-06-03 Guideworks, Llc Systems and methods for recording and playing back programs having desirable recording attributes
US20100138693A1 (en) * 2008-11-28 2010-06-03 Hitachi Automotive Systems, Ltd. Multi-Core Processing System for Vehicle Control Or An Internal Combustion Engine Controller
US7735088B1 (en) * 2003-08-18 2010-06-08 Cray Inc. Scheduling synchronization of programs running as streams on multiple processors
US20100211815A1 (en) * 2009-01-09 2010-08-19 Computer Associates Think, Inc. System and method for modifying execution of scripts for a job scheduler using deontic logic
US7805727B2 (en) 1992-09-30 2010-09-28 Apple Inc. Execution control for processor tasks
DE10065419B4 (en) * 2000-12-27 2011-01-20 Siemens Ag Industrial Control with isochronous running level model
US20110252422A1 (en) * 2010-04-07 2011-10-13 Apple Inc. Opportunistic Multitasking
CN101652777B (en) 2007-03-30 2012-05-30 微软公司 Query generation using environment configuration
US8229283B2 (en) 2005-04-01 2012-07-24 Rovi Guides, Inc. System and method for quality marking of a recording
USRE43760E1 (en) 2001-05-09 2012-10-23 Ulrich Abel Adjusting connection bandwidth in a data network
US8307194B1 (en) 2003-08-18 2012-11-06 Cray Inc. Relaxed memory consistency model
US8407703B1 (en) * 1994-01-27 2013-03-26 International Business Machines Corporation Quiensce termination/suspension in a multithreaded enviroment
US8528032B2 (en) 1998-07-14 2013-09-03 United Video Properties, Inc. Client-server based interactive television program guide system with remote server recording
US8806533B1 (en) 2004-10-08 2014-08-12 United Video Properties, Inc. System and method for using television information codes
US8989561B1 (en) 2008-05-29 2015-03-24 Rovi Guides, Inc. Systems and methods for alerting users of the postponed recording of programs
US9071872B2 (en) 2003-01-30 2015-06-30 Rovi Guides, Inc. Interactive television systems with digital video recording and adjustable reminders
US9075861B2 (en) 2006-03-06 2015-07-07 Veveo, Inc. Methods and systems for segmenting relative user preferences into fine-grain and coarse-grain collections
US9125169B2 (en) 2011-12-23 2015-09-01 Rovi Guides, Inc. Methods and systems for performing actions based on location-based rules
US20150268994A1 (en) * 2014-03-20 2015-09-24 Fujitsu Limited Information processing device and action switching method
US9166714B2 (en) 2009-09-11 2015-10-20 Veveo, Inc. Method of and system for presenting enriched video viewing analytics
US9191722B2 (en) 1997-07-21 2015-11-17 Rovi Guides, Inc. System and method for modifying advertisement responsive to EPG information
US9215504B2 (en) 2006-10-06 2015-12-15 Rovi Guides, Inc. Systems and methods for acquiring, categorizing and delivering media in interactive media guidance applications
US9294799B2 (en) 2000-10-11 2016-03-22 Rovi Guides, Inc. Systems and methods for providing storage of data on servers in an on-demand media delivery system
US9319735B2 (en) 1995-06-07 2016-04-19 Rovi Guides, Inc. Electronic television program guide schedule system and method with data feed access
US9326025B2 (en) 2007-03-09 2016-04-26 Rovi Technologies Corporation Media content search results ranked by popularity
US9336070B1 (en) 2013-06-07 2016-05-10 Apple Inc. Throttling of application access to resources
US9426509B2 (en) 1998-08-21 2016-08-23 Rovi Guides, Inc. Client-server electronic program guide
US9736524B2 (en) 2011-01-06 2017-08-15 Veveo, Inc. Methods of and systems for content search based on environment sampling
US9749693B2 (en) 2006-03-24 2017-08-29 Rovi Guides, Inc. Interactive media guidance application with intelligent navigation and display features

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5265257A (en) * 1990-06-22 1993-11-23 Digital Equipment Corporation Fast arbiter having easy scaling for large numbers of requesters, large numbers of resource types with multiple instances of each type, and selectable queuing disciplines
US5247675A (en) * 1991-08-09 1993-09-21 International Business Machines Corporation Preemptive and non-preemptive scheduling and execution of program threads in a multitasking operating system
US5844980A (en) * 1993-03-03 1998-12-01 Siemens Business Communication Systems, Inc. Queue managing system and method
US5487170A (en) * 1993-12-16 1996-01-23 International Business Machines Corporation Data processing system having dynamic priority task scheduling capabilities
WO1996017306A3 (en) * 1994-11-21 1996-10-17 Oracle Corp Media server
US5987492A (en) * 1997-10-31 1999-11-16 Sun Microsystems, Inc. Method and apparatus for processor sharing
CN100474883C (en) 2002-09-13 2009-04-01 株式会社理光 Image forming apparatus and method
CN1310146C (en) * 2004-02-09 2007-04-11 中兴通讯股份有限公司 Modular implement method for operating system of single-chip microcomputer
CN1317640C (en) * 2004-08-31 2007-05-23 华为技术有限公司 Multi-task application software module management method in real-time operating system environment
US8510737B2 (en) 2005-01-07 2013-08-13 Samsung Electronics Co., Ltd. Method and system for prioritizing tasks made available by devices in a network
CN103293967A (en) * 2012-02-29 2013-09-11 陕西省地方电力(集团)有限公司 Multi-task control method for intelligent meter reading terminal
CN102937915B (en) * 2012-11-28 2016-02-24 中国人民解放军国防科学技术大学 Hardware lock for multi-core processor implemented method and apparatus

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3618045A (en) * 1969-05-05 1971-11-02 Honeywell Inf Systems Management control subsystem for multiprogrammed data processing system
US3643227A (en) * 1969-09-15 1972-02-15 Fairchild Camera Instr Co Job flow and multiprocessor operation control system
US4001783A (en) * 1975-03-26 1977-01-04 Honeywell Information Systems, Inc. Priority interrupt mechanism
US4047161A (en) * 1976-04-30 1977-09-06 International Business Machines Corporation Task management apparatus
US4084228A (en) * 1973-11-30 1978-04-11 Compagnie Honeywell Bull Process management structures and hardware/firmware control
US4228495A (en) * 1978-12-19 1980-10-14 Allen-Bradley Company Multiprocessor numerical control system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3618045A (en) * 1969-05-05 1971-11-02 Honeywell Inf Systems Management control subsystem for multiprogrammed data processing system
US3643227A (en) * 1969-09-15 1972-02-15 Fairchild Camera Instr Co Job flow and multiprocessor operation control system
US4084228A (en) * 1973-11-30 1978-04-11 Compagnie Honeywell Bull Process management structures and hardware/firmware control
US4001783A (en) * 1975-03-26 1977-01-04 Honeywell Information Systems, Inc. Priority interrupt mechanism
US4047161A (en) * 1976-04-30 1977-09-06 International Business Machines Corporation Task management apparatus
US4228495A (en) * 1978-12-19 1980-10-14 Allen-Bradley Company Multiprocessor numerical control system

Cited By (167)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5377352A (en) * 1988-05-27 1994-12-27 Hitachi, Ltd. Method of scheduling tasks with priority to interrupted task locking shared resource
US5361365A (en) * 1989-11-06 1994-11-01 Sharp Kabushiki Kaisha Microprocessor for selectively performing cold and warm starts
US5553287A (en) * 1989-11-28 1996-09-03 International Business Machines Corporation Methods and apparatus for dynamically using floating master interlock
US5168570A (en) * 1989-12-29 1992-12-01 Supercomputer Systems Limited Partnership Method and apparatus for a multiple request toggling priority system
US5208914A (en) * 1989-12-29 1993-05-04 Superconductor Systems Limited Partnership Method and apparatus for non-sequential resource access
US5452452A (en) * 1990-06-11 1995-09-19 Cray Research, Inc. System having integrated dispatcher for self scheduling processors to execute multiple types of processes
WO1991020041A1 (en) * 1990-06-11 1991-12-26 Supercomputer Systems Limited Partnership Multiple request toggling priority arbitration system
US5506988A (en) * 1990-06-26 1996-04-09 Siemens Aktiengesellschaft Program-controlled communication installation
US5249297A (en) * 1991-04-29 1993-09-28 Hewlett-Packard Company Methods and apparatus for carrying out transactions in a computer system
US5392429A (en) * 1991-10-11 1995-02-21 At&T Corp. Method of operating a multiprocessor computer to solve a set of simultaneous equations
US5465335A (en) * 1991-10-15 1995-11-07 Hewlett-Packard Company Hardware-configured operating system kernel having a parallel-searchable event queue for a multitasking processor
US5307482A (en) * 1992-01-28 1994-04-26 International Business Machines Corp. Computer, non-maskable interrupt trace routine override
US5640563A (en) * 1992-01-31 1997-06-17 International Business Machines Corporation Multi-media computer operating system and method
US5430874A (en) * 1992-03-06 1995-07-04 Hitachi, Limited Control method and system for managing memory control blocks of programmed tasks in a multi-processing system
US5715474A (en) * 1992-04-30 1998-02-03 Motorola, Inc. Simultaneous control of radio frequency modem in a multi-tasking system using a single session manager program with separate command queue for each application program
US5392433A (en) * 1992-09-25 1995-02-21 International Business Machines Corporation Method and apparatus for intraprocess locking of a shared resource in a computer system
US7805727B2 (en) 1992-09-30 2010-09-28 Apple Inc. Execution control for processor tasks
US5471618A (en) * 1992-11-30 1995-11-28 3Com Corporation System for classifying input/output events for processes servicing the events
US5513354A (en) * 1992-12-18 1996-04-30 International Business Machines Corporation Fault tolerant load management system and method
US5727210A (en) * 1992-12-18 1998-03-10 International Business Machines Corporation Fault tolerant load management system and method
US20080250433A1 (en) * 1993-07-19 2008-10-09 Apple Inc. Object-oriented operating system
US20090193442A2 (en) * 1993-07-19 2009-07-30 Object Technology Licensing Corporation Object-oriented operating system
US5428789A (en) * 1993-08-27 1995-06-27 Waldron, Iii; Theodore C. Method and apparatus for optimizing user response time in a priority preemptive operating system
US8407703B1 (en) * 1994-01-27 2013-03-26 International Business Machines Corporation Quiensce termination/suspension in a multithreaded enviroment
US5504904A (en) * 1994-02-23 1996-04-02 International Business Machines Corporation Personal computer having operating system definition file for configuring computer system
US6260058B1 (en) * 1994-07-19 2001-07-10 Robert Bosch Gmbh Process for controlling technological operations or processes
US5513351A (en) * 1994-07-28 1996-04-30 International Business Machines Corporation Protecting a system during system maintenance by usage of temporary filenames in an alias table
US5511220A (en) * 1994-09-01 1996-04-23 Perlman; Noah Multi-user computer system with a clock driven batch dispatching mechanism
US5742825A (en) * 1994-09-30 1998-04-21 Microsoft Corporation Operating system for office machines
US9319735B2 (en) 1995-06-07 2016-04-19 Rovi Guides, Inc. Electronic television program guide schedule system and method with data feed access
US6049867A (en) * 1995-06-07 2000-04-11 International Business Machines Corporation Method and system for multi-thread switching only when a cache miss occurs at a second or higher level
US5940612A (en) * 1995-09-27 1999-08-17 International Business Machines Corporation System and method for queuing of tasks in a multiprocessing system
US6078942A (en) * 1996-04-25 2000-06-20 Microsoft Corporation Resource management for multimedia devices in a computer
US8955013B2 (en) 1996-06-14 2015-02-10 Rovi Guides, Inc. Television schedule system and method of operation for multiple program occurrences
US20080077957A1 (en) * 1996-06-14 2008-03-27 Starsight Telecast, Inc. Television schedule system and method of operation for multiple program occurrences
US8522282B2 (en) 1996-06-14 2013-08-27 Starsight Telecast, Inc. Television schedule system and method of operation for multiple program occurrences
US5954792A (en) * 1996-12-30 1999-09-21 Cadence Design Systems, Inc. Method for schedule validation of embedded systems
US6829764B1 (en) * 1997-06-23 2004-12-07 International Business Machines Corporation System and method for maximizing usage of computer resources in scheduling of application tasks
US7036002B1 (en) * 1997-06-26 2006-04-25 Cp8 Technologies System and method for using multiple working memories to improve microprocessor security
US6408324B1 (en) * 1997-07-03 2002-06-18 Trw Inc. Operating system having a non-interrupt cooperative multi-tasking kernel and a method of controlling a plurality of processes with the system
US9191722B2 (en) 1997-07-21 2015-11-17 Rovi Guides, Inc. System and method for modifying advertisement responsive to EPG information
US6182120B1 (en) * 1997-09-30 2001-01-30 International Business Machines Corporation Method and system for scheduling queued messages based on queue delay and queue priority
US5999963A (en) * 1997-11-07 1999-12-07 Lucent Technologies, Inc. Move-to-rear list scheduling
US6510460B1 (en) * 1997-12-18 2003-01-21 Sun Microsystems, Inc. Method and apparatus for enforcing locking invariants in multi-threaded systems
US6549928B1 (en) * 1998-04-29 2003-04-15 Xerox Corporation Machine control integrating event based model with task based model
US6678713B1 (en) * 1998-04-29 2004-01-13 Xerox Corporation Machine control using a schedulerlock construct
US9021538B2 (en) 1998-07-14 2015-04-28 Rovi Guides, Inc. Client-server based interactive guide with server recording
US9232254B2 (en) 1998-07-14 2016-01-05 Rovi Guides, Inc. Client-server based interactive television guide with server recording
US9154843B2 (en) 1998-07-14 2015-10-06 Rovi Guides, Inc. Client-server based interactive guide with server recording
US9118948B2 (en) 1998-07-14 2015-08-25 Rovi Guides, Inc. Client-server based interactive guide with server recording
US9055319B2 (en) 1998-07-14 2015-06-09 Rovi Guides, Inc. Interactive guide with recording
US9226006B2 (en) 1998-07-14 2015-12-29 Rovi Guides, Inc. Client-server based interactive guide with server recording
US8776126B2 (en) 1998-07-14 2014-07-08 United Video Properties, Inc. Client-server based interactive television guide with server recording
US9055318B2 (en) 1998-07-14 2015-06-09 Rovi Guides, Inc. Client-server based interactive guide with server storage
US8528032B2 (en) 1998-07-14 2013-09-03 United Video Properties, Inc. Client-server based interactive television program guide system with remote server recording
US6215559B1 (en) * 1998-07-31 2001-04-10 Eastman Kodak Company Image queing in photofinishing
WO2000006084A3 (en) * 1998-07-31 2000-08-03 Integrated Systems Design Cent Integrated hardware and software task control executive
WO2000006084A2 (en) * 1998-07-31 2000-02-10 Integrated Systems Design Center, Inc. Integrated hardware and software task control executive
US9426509B2 (en) 1998-08-21 2016-08-23 Rovi Guides, Inc. Client-server electronic program guide
US6105050A (en) * 1998-08-25 2000-08-15 International Business Machines Corporation System for resource lock/unlock capability in multithreaded computer environment
US6105049A (en) * 1998-08-25 2000-08-15 International Business Machines Corporation Resource lock/unlock capability in multithreaded computer environment
US6112222A (en) * 1998-08-25 2000-08-29 International Business Machines Corporation Method for resource lock/unlock capability in multithreaded computer environment
US6334159B1 (en) * 1998-12-22 2001-12-25 Unisys Corporation Method and apparatus for scheduling requests within a data processing system
US6633942B1 (en) * 1999-08-12 2003-10-14 Rockwell Automation Technologies, Inc. Distributed real-time operating system providing integrated interrupt management
US9294799B2 (en) 2000-10-11 2016-03-22 Rovi Guides, Inc. Systems and methods for providing storage of data on servers in an on-demand media delivery system
WO2002052370A2 (en) * 2000-12-26 2002-07-04 Bull Hn Information Systems Inc. Software and data processing system with priority queue dispatching
WO2002052370A3 (en) * 2000-12-26 2003-01-23 Bull Hn Information Syst Software and data processing system with priority queue dispatching
DE10065417B4 (en) * 2000-12-27 2011-07-21 Siemens AG, 80333 Programming cyclical machines
US20020082721A1 (en) * 2000-12-27 2002-06-27 Armin Amrhein Programming of cyclical machines
US6941175B2 (en) * 2000-12-27 2005-09-06 Siemens Aktiengesellschaft Method of operating an industrial controller
US6978190B2 (en) * 2000-12-27 2005-12-20 Siemens Aktiengesellschaft Programming of cyclical machines
DE10065419B4 (en) * 2000-12-27 2011-01-20 Siemens Ag Industrial Control with isochronous running level model
US20020082718A1 (en) * 2000-12-27 2002-06-27 Armin Amrhein Method of operating an industrial controller
US20090310937A1 (en) * 2001-02-21 2009-12-17 United Video Properties, Inc. Systems and methods for interactive program guides with personal video recording features
US9055322B2 (en) 2001-02-21 2015-06-09 Rovi Guides, Inc. Systems and methods for interactive program guides with personal video recording features
US20080184297A1 (en) * 2001-02-21 2008-07-31 Ellis Michael D Systems and methods for interactive program guides with personal video recording features
US9930374B2 (en) 2001-02-21 2018-03-27 Rovi Guides, Inc. Systems and methods for interactive program guides with personal video recording features
US8457475B2 (en) 2001-02-21 2013-06-04 United Video Properties, Inc. Systems and methods for interactive program guides with personal video recording features
US8768147B2 (en) 2001-02-21 2014-07-01 United Video Properties, Inc. Systems and methods for interactive program guides with personal video recording features
USRE43760E1 (en) 2001-05-09 2012-10-23 Ulrich Abel Adjusting connection bandwidth in a data network
US20030009508A1 (en) * 2001-06-26 2003-01-09 Troia Terry A. Method and system for providing processor task scheduling
US20030037091A1 (en) * 2001-08-09 2003-02-20 Kozo Nishimura Task scheduling device
US20040139442A1 (en) * 2001-09-20 2004-07-15 Keiichi Miyamoto Task switching system, task switching method and dsp modem
US8387056B2 (en) 2001-09-26 2013-02-26 Access Co., Ltd. Method for dynamically enabling the expansion of a computer operating system
US20100115525A1 (en) * 2001-09-26 2010-05-06 Palmsource, Inc. Method for dynamically enabling the expansion of a computer operating system
US7647591B1 (en) * 2001-09-26 2010-01-12 Palmsource Inc. Method for dynamically enabling the expansion of a computer operating system
US7305675B1 (en) * 2002-01-11 2007-12-04 Advanced Micro Devices, Inc. Processing tasks with failure recovery
US20030198462A1 (en) * 2002-04-23 2003-10-23 Jim Bumgardner Conflict Manager for a Video Recorder
US20030206719A1 (en) * 2002-04-23 2003-11-06 Jim Bumgardner Storage Management for a Video Recorder
US7774816B2 (en) 2002-04-23 2010-08-10 Rovi Technologies Corporation Conflict manager for a video recorder
US20030225817A1 (en) * 2002-06-04 2003-12-04 Prashanth Ishwar Concurrent execution of kernel work and non-kernel work in operating systems with single-threaded kernel
US9369741B2 (en) 2003-01-30 2016-06-14 Rovi Guides, Inc. Interactive television systems with digital video recording and adjustable reminders
US9071872B2 (en) 2003-01-30 2015-06-30 Rovi Guides, Inc. Interactive television systems with digital video recording and adjustable reminders
US20040156614A1 (en) * 2003-02-10 2004-08-12 Pioneer Digital Technologies, Inc. Tuner sharing video recorder system architecture
US8116611B2 (en) * 2003-02-10 2012-02-14 Aptiv Digital, Inc. Tuner sharing video recorder system architecture
US20040213557A1 (en) * 2003-04-23 2004-10-28 Pioneer Digital Technologies, Inc. Non-hierarchical interface screens for use in a video recorder
US7577816B2 (en) 2003-08-18 2009-08-18 Cray Inc. Remote translation mechanism for a multinode system
US7743223B2 (en) 2003-08-18 2010-06-22 Cray Inc. Decoupling of write address from its associated write data in a store to a shared memory in a multiprocessor system
US7735088B1 (en) * 2003-08-18 2010-06-08 Cray Inc. Scheduling synchronization of programs running as streams on multiple processors
US7793073B2 (en) 2003-08-18 2010-09-07 Cray Inc. Method and apparatus for indirectly addressed vector load-add-store across multi-processors
US7503048B1 (en) 2003-08-18 2009-03-10 Cray Incorporated Scheduling synchronization of programs running as streams on multiple processors
US7519771B1 (en) 2003-08-18 2009-04-14 Cray Inc. System and method for processing memory instructions using a forced order queue
US20050044128A1 (en) * 2003-08-18 2005-02-24 Scott Steven L. Decoupled store address and data in a multiprocessor system
US8307194B1 (en) 2003-08-18 2012-11-06 Cray Inc. Relaxed memory consistency model
US20050044340A1 (en) * 2003-08-18 2005-02-24 Kitrick Sheets Remote translation mechanism for a multinode system
US20070283127A1 (en) * 2003-08-18 2007-12-06 Cray Inc. Method and apparatus for indirectly addressed vector load-add-store across multi-processors
US7543133B1 (en) 2003-08-18 2009-06-02 Cray Inc. Latency tolerant distributed shared memory multiprocessor computer
US20050086665A1 (en) * 2003-10-16 2005-04-21 Matsushita Electric Industrial Co., Ltd. Autonomous device driver
US8707317B2 (en) * 2004-04-30 2014-04-22 Microsoft Corporation Reserving a fixed amount of hardware resources of a multimedia console for system application and controlling the unreserved resources by the multimedia application
US20050262255A1 (en) * 2004-04-30 2005-11-24 Microsoft Corporation System applications in a multimedia console
US20050267792A1 (en) * 2004-05-28 2005-12-01 Sumit Mehrotra Method and system for laboratory management
US8171474B2 (en) 2004-10-01 2012-05-01 Serguei Mankovski System and method for managing, scheduling, controlling and monitoring execution of jobs by a job scheduler utilizing a publish/subscription interface
US20060095914A1 (en) * 2004-10-01 2006-05-04 Serguei Mankovski System and method for job scheduling
US8806533B1 (en) 2004-10-08 2014-08-12 United Video Properties, Inc. System and method for using television information codes
US8959521B2 (en) 2004-10-14 2015-02-17 International Business Machines Corporation Apparatus and methods for performing computer system maintenance and notification activities in an opportunistic manner
US20080177682A1 (en) * 2004-10-14 2008-07-24 Jacob Lorien Moilanen Autonomic SMT System Tuning
US20060085368A1 (en) * 2004-10-14 2006-04-20 International Business Machines Corporation Autonomic SMT System tuning
US7669204B2 (en) * 2004-10-14 2010-02-23 International Business Machines Corporation Autonomic SMT System tuning
US20080178186A1 (en) * 2004-10-14 2008-07-24 International Business Machines Corporation Apparatus and Methods for Performing Computer System Maintenance and Notification Activities in an Opportunistic Manner
US7814490B2 (en) 2004-10-14 2010-10-12 International Business Machines Corporation Apparatus and methods for performing computer system maintenance and notification activities in an opportunistic manner
US8370840B2 (en) 2004-10-14 2013-02-05 International Business Machines Corporation Apparatus and methods for performing computer system maintenance and notification activities in an opportunistic manner
US8229283B2 (en) 2005-04-01 2012-07-24 Rovi Guides, Inc. System and method for quality marking of a recording
US8625971B2 (en) 2005-09-30 2014-01-07 Rovi Guides, Inc. Systems and methods for recording and playing back programs having desirable recording attributes
US9171580B2 (en) 2005-09-30 2015-10-27 Rovi Guides, Inc. Systems and methods for recording and playing back programs having desirable recording attributes
US20100135639A1 (en) * 2005-09-30 2010-06-03 Guideworks, Llc Systems and methods for recording and playing back programs having desirable recording attributes
US20070168539A1 (en) * 2005-12-29 2007-07-19 Guideworks, Llc Systems and methods for managing a status change of a multimedia asset in multimedia delivery systems
US20070174336A1 (en) * 2005-12-29 2007-07-26 Guideworks, Llc Systems and methods for resolving conflicts and managing system resources in multimedia delivery systems
US9374560B2 (en) 2005-12-29 2016-06-21 Rovi Guides, Inc. Systems and methods for managing a status change of a multimedia asset in multimedia delivery systems
US7765235B2 (en) 2005-12-29 2010-07-27 Rovi Guides, Inc. Systems and methods for resolving conflicts and managing system resources in multimedia delivery systems
US8214869B2 (en) 2005-12-29 2012-07-03 Rovi Guides, Inc. Systems and methods for managing a status change of a multimedia asset in multimedia delivery systems
US9128987B2 (en) 2006-03-06 2015-09-08 Veveo, Inc. Methods and systems for selecting and presenting content based on a comparison of preference signatures from multiple users
US9075861B2 (en) 2006-03-06 2015-07-07 Veveo, Inc. Methods and systems for segmenting relative user preferences into fine-grain and coarse-grain collections
US9092503B2 (en) 2006-03-06 2015-07-28 Veveo, Inc. Methods and systems for selecting and presenting content based on dynamically identifying microgenres associated with the content
US9749693B2 (en) 2006-03-24 2017-08-29 Rovi Guides, Inc. Interactive media guidance application with intelligent navigation and display features
US20090150888A1 (en) * 2006-04-03 2009-06-11 Beijing Watch Data System Co., Ltd. Embedded operating system of smart card and the method for processing the task
US8266619B2 (en) * 2006-04-03 2012-09-11 Beijing Watch Data System Co., Ltd. Embedded operating system architecture for smart card
US20070250834A1 (en) * 2006-04-19 2007-10-25 Orion Electric Co., Ltd. Information processing device including manipulation task reservation function, manipulation task reservation processing program and manipulation task reservation processing method
US20080046935A1 (en) * 2006-08-18 2008-02-21 Krakirian Haig H System and method for displaying program guide information
US9215504B2 (en) 2006-10-06 2015-12-15 Rovi Guides, Inc. Systems and methods for acquiring, categorizing and delivering media in interactive media guidance applications
US20080140896A1 (en) * 2006-11-10 2008-06-12 Seiko Epson Corporation Processor and interrupt controlling method
US7853743B2 (en) * 2006-11-10 2010-12-14 Seiko Epson Corporation Processor and interrupt controlling method
US9326025B2 (en) 2007-03-09 2016-04-26 Rovi Technologies Corporation Media content search results ranked by popularity
CN101652777B (en) 2007-03-30 2012-05-30 微软公司 Query generation using environment configuration
US20090007123A1 (en) * 2007-06-28 2009-01-01 Samsung Electronics Co., Ltd. Dynamic Application Scheduler in a Polling System
US8141079B2 (en) * 2007-06-28 2012-03-20 Samsung Electronics Co., Ltd. Dynamic application scheduler in a polling system
US8126860B2 (en) * 2007-07-17 2012-02-28 Ricoh Company, Limited Method and apparatus for processing data
US20090024665A1 (en) * 2007-07-17 2009-01-22 Ricoh Company, Limited Method and apparatus for processing data
US20090063242A1 (en) * 2007-09-04 2009-03-05 International Business Machines Corporation System and method for providing automatic task assignment and notification
US9953282B2 (en) 2007-09-04 2018-04-24 International Business Machines Corporation System and method for providing automatic task assignment and notification
US9984343B2 (en) 2007-09-04 2018-05-29 International Business Machines Corporation System and method for providing automatic task assignment and notification
US20090208961A1 (en) * 2008-02-12 2009-08-20 Pacific Biosciences Of California, Inc. Compositions and methods for use in analytical reactions
US8989561B1 (en) 2008-05-29 2015-03-24 Rovi Guides, Inc. Systems and methods for alerting users of the postponed recording of programs
US9723363B2 (en) 2008-05-29 2017-08-01 Rovi Guides, Inc. Systems and methods for alerting users of the postponed recording of programs
US8417990B2 (en) * 2008-11-28 2013-04-09 Hitachi Automotive Systems, Ltd. Multi-core processing system for vehicle control or an internal combustion engine controller
US20100138693A1 (en) * 2008-11-28 2010-06-03 Hitachi Automotive Systems, Ltd. Multi-Core Processing System for Vehicle Control Or An Internal Combustion Engine Controller
US20100211815A1 (en) * 2009-01-09 2010-08-19 Computer Associates Think, Inc. System and method for modifying execution of scripts for a job scheduler using deontic logic
US8266477B2 (en) 2009-01-09 2012-09-11 Ca, Inc. System and method for modifying execution of scripts for a job scheduler using deontic logic
US9166714B2 (en) 2009-09-11 2015-10-20 Veveo, Inc. Method of and system for presenting enriched video viewing analytics
US20110252430A1 (en) * 2010-04-07 2011-10-13 Apple Inc. Opportunistic Multitasking
US9104476B2 (en) 2010-04-07 2015-08-11 Apple Inc. Opportunistic multitasking of VOIP applications
US20110252422A1 (en) * 2010-04-07 2011-10-13 Apple Inc. Opportunistic Multitasking
US9135059B2 (en) 2010-04-07 2015-09-15 Apple Inc. Opportunistic multitasking
US9736524B2 (en) 2011-01-06 2017-08-15 Veveo, Inc. Methods of and systems for content search based on environment sampling
US9125169B2 (en) 2011-12-23 2015-09-01 Rovi Guides, Inc. Methods and systems for performing actions based on location-based rules
US9336070B1 (en) 2013-06-07 2016-05-10 Apple Inc. Throttling of application access to resources
US9740539B2 (en) * 2014-03-20 2017-08-22 Fujitsu Limited Information processing device, action switching method and recording medium storing switching program
US20150268994A1 (en) * 2014-03-20 2015-09-24 Fujitsu Limited Information processing device and action switching method

Also Published As

Publication number Publication date Type
EP0332148A2 (en) 1989-09-13 application
EP0332148A3 (en) 1990-08-08 application
JPH01316831A (en) 1989-12-21 application
CN1038712A (en) 1990-01-10 application

Similar Documents

Publication Publication Date Title
Stankovic et al. The Spring kernel: a new paradigm for real-time operating systems
Katcher et al. Engineering and analysis of fixed priority schedulers
US5515538A (en) Apparatus and method for interrupt handling in a multi-threaded operating system kernel
US5701495A (en) Scalable system interrupt structure for a multi-processing system
US5418952A (en) Parallel processor cell computer system
US5367678A (en) Multiprocessor system having statically determining resource allocation schedule at compile time and the using of static schedule with processor signals to control the execution time dynamically
US5636124A (en) Multitasking industrial controller
US6505229B1 (en) Method for allowing multiple processing threads and tasks to execute on one or more processor units for embedded real-time processor systems
Stankovic et al. What is predictability for real-time systems?
US6021425A (en) System and method for optimizing dispatch latency of tasks in a data processing system
US6687903B1 (en) Inhibiting starvation in a multitasking operating system
US6360243B1 (en) Method, device and article of manufacture for implementing a real-time task scheduling accelerator
Mantegazza et al. RTAI: Real time application interface
US5542088A (en) Method and apparatus for enabling control of task execution
US5630130A (en) Multi-tasking low-power controller having multiple program counters
US4149243A (en) Distributed control architecture with post and wait logic
US5911065A (en) System and method for providing cooperative interrupts in a preemptive task scheduling environment
US6128672A (en) Data transfer using software interrupt service routine between host processor and external device with queue of host processor and hardware queue pointers on external device
US5630128A (en) Controlled scheduling of program threads in a multitasking operating system
US5701439A (en) Combined discrete-event and continuous model simulation and analysis tool
US5768599A (en) Interrupt managing system for real-time operating system
US6473780B1 (en) Scheduling of direct memory access
US6148322A (en) Processing unit with an improved ability to coordinate the execution of multiple tasks with varying priorities
US6128728A (en) Virtual shadow registers and virtual register windows
US5485626A (en) Architectural enhancements for parallel computer systems utilizing encapsulation of queuing allowing small grain processing

Legal Events

Date Code Title Description
AS Assignment

Owner name: HONEYWELL INC., HONEYWELL PLAZA, MINNEAPOLIS, MN 5

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:FLETCHER, MITCHELL S.;SEMMA, RICHARD P.;REEL/FRAME:004895/0840

Effective date: 19880520

FPAY Fee payment

Year of fee payment: 4

REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees
FP Expired due to failure to pay maintenance fee

Effective date: 19990430